Arc stop

ABSTRACT

Various embodiments may be generally directed to a welding system that monitors an output of the welding system to determine if an output arc should be extinguished or maintained. The welding system can compare an arc voltage output to a voltage threshold and a temporal threshold. When the arc voltage output exceeds the voltage threshold in an uninterrupted manner for the duration of the temporal threshold, an output weld current can be stopped. In turn, the output arc can be broken or extinguished. After a predetermined amount of time, the power source can be re-engaged to prepare for re-ignition of another arc. By tracking the amount of time the arc voltage output exceeds the predetermined threshold, a probability of unwanted arc outs can be reduced or minimized while still providing quick and reliable arc breaking when desired.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/683,947, filed on Aug. 23, 2017, which claims the benefit of U.S.Provisional Patent Application No. 62/382,019, filed on Aug. 31, 2016,the disclosure of which is incorporated by reference herein in itsentirety.

TECHNICAL FIELD

The present embodiments are related to power supplies for welding typepower, that is, power generally used for welding, cutting, or heating.

BACKGROUND

Often, during a welding process, a welder may deliberately retract anelectrode from a workpiece. In some instances, the welder may retractthe electrode from the workpiece so as to control a weld pool (e.g., atemperature of a weld puddle). Under such a scenario, the welder may notwant the retraction of the electrode to cause the output arc to break orextinguish. That is, certain retractions of the electrode from theworkpiece may be intended to be a short break in the welding process. Inother instances, the welder may retract the electrode from the workpiecewith the intention to cause the output arc to break. Under such ascenario, the welder expects the output arc to break.

Many conventional welding systems are not capable of distinguishing awelder's movement of the electrode relative to the workpiece as being ashort break in the welding process or as being a first step towardsdeliberately breaking the output arc. As a result, many conventionalwelding systems are simply designed to attempt to maintain the arcduring any retraction of the electrode by the welder. These conventionalwelding systems consequently adjust operation to maintain the arc insuch circumstances, resulting in a long arc that can be detrimental tothe welding process and weld quality. These shortcomings are common inconventional manual metal arc welding (MMA) systems during MMA weldingprocesses.

It is with respect to these and other considerations that the presentdisclosure is provided.

SUMMARY OF THE INVENTION

The following presents a simplified summary in order to provide a basicunderstanding of some novel embodiments described herein. This summaryis not an extensive overview, and it is not intended to identifykey/critical elements or to delineate the scope thereof. Its solepurpose is to present some concepts in a simplified form as a prelude tothe more detailed description that is presented later.

Various embodiments may be generally directed to a welding system thatmonitors an output of the welding system to determine if an output arcshould be extinguished or maintained. The welding system can compare anarc voltage output to a voltage threshold and a temporal threshold. Whenthe arc voltage output exceeds the voltage threshold in an uninterruptedmanner for the duration of the temporal threshold, an output weldcurrent can be stopped. In turn, the output arc can be broken orextinguished. After a predetermined amount of time, the power source canbe re-engaged to prepare for re-ignition of another arc. By tracking theamount of time the arc voltage output exceeds the predeterminedthreshold, a probability of unwanted arc outs can be reduced orminimized while still providing quick and reliable arc breaking whendesired.

To the accomplishment of the foregoing and related ends, certainillustrative aspects are described herein in connection with thefollowing description and the annexed drawings. These aspects areindicative of the various ways in which the principles disclosed hereincan be practiced and all aspects and equivalents thereof are intended tobe within the scope of the claimed subject matter. Other advantages andnovel features will become apparent from the following detaileddescription when considered in conjunction with the drawings.

DESCRIPTION OF FIGURES

FIG. 1 illustrates a welding system.

FIG. 2 illustrates an exemplary output monitoring technique implementedby the welding system depicted in FIG. 1 .

DESCRIPTION OF EMBODIMENTS

FIG. 1 illustrates a portion of a welding system 100 for managing anoutput based on the arc management techniques described herein. Thewelding system 100 can be used for a variety of welding processesincluding, for example, MMA welding processes. The welding system 100can reduce unwanted arc outs and can provide reliable and quick arcbreaking when desired by a welder using the welding system 100.

As shown in FIG. 1 , the welding system 100 can include an outputmonitor 102 and a control module 104. The control module 104 can becoupled to the output monitor 102. The output monitor 102 can receiveoutput information 106. The output information 106 can be informationrelated to an output of a welding machine such as, for example, outputcurrent, output voltage, and/or output power. The output information 106can be provided to the output monitor 102 from one or more outputsensors of the welding machine.

Based on the received output information 106, the output monitor 102 canmonitor a welding process being implemented by a welder and candetermine when an arc is desired to be extinguished or maintained by thewelder. That is, the output monitor 102 can be provided with information(e.g., the output information 106) to enable the output monitor 102 topredict when an output arc should be maintained or when an output arcshould be extinguished.

In various embodiments, the output monitor 102 can monitor and/or filteran output voltage over time during a welding process (e.g., an MMAwelding process). The output monitor 102 can observe the output voltageover time (e.g., as indicator of output arc voltage) and can compare theoutput voltage to a predetermined threshold. As an example, when theoutput voltage (e.g., as indicated in the received output information106) exceeds the predetermined threshold for a predetermined amount oftime, the output monitor 102 can determine that the output arc is to bebroken and/or extinguished. When the output voltage fails to exceedeither the predetermined arc voltage threshold or the predetermined timethreshold, then the output monitor 102 can determine that the output arcis to be maintained.

By comparing the output arc voltage to a voltage threshold level as wellas by tracking a temporal threshold, the output monitor 102 can betterdistinguish when an electrode has been retracted by a welder with thegoal of breaking the arc compared to when the electrode has beenretracted as only part of a short break in the welding process (i.e.,where an arc break is not desired by the welder).

When the predetermined arc voltage threshold has been exceeded for thepredetermined amount of time, the output monitor 102 can determine thatthe arc is to be broken. In response, the output monitor 102 can providea signal 108 to the control module 104 indicating the same.Specifically, the output monitor 102 can provide the signal 108 to thecontrol module 104 that can provide a continuous update of the output.The control module 104 can use information provided by the outputmonitor 102 to govern operation of the welding system 100. For example,the control module 104 can determine if the welding system 100 is to beoperated to maintain an output arc or if the arc is to be broken. Thecontrol module 104 can provide control information 110 to controloperation of the welding system 100. The control information 110 can beprovided to other constituent components of the welding system 100 (notdepicted in FIG. 1 for simplicity). The control information 110 cancause an output arc to be maintained or broken. For example, the controlinformation 110 can cause an output welding current to be stopped or nolonger provided.

The arc voltage threshold and time threshold used by the output monitor102 can be established such that when the thresholds are exceeded theoutput weld current can be immediately cut off. The arc voltagethreshold and time threshold (which together can be considered to befilter parameters used by the output monitor 102) can be adjusted andvaried for different types of welding. Overall, these filter parameterscan be optimized so that the welding system 100 can operate with areduced or minimal probability of unwanted arc outs and while alsoproviding reliable and fast arc breaking. Further, the output monitor102 and the control module 104 can operate such that when an arc isextinguished, the power source of the welding system 100 can supplyvoltage to the output again after a few milliseconds to be ready forignition to start a next weld.

The output monitor 102 can implement filtering/monitoring of the outputthat can be varied and/or fine-tuned for a number of processes andoperational conditions. Specifically, the arc voltage threshold andtemporal threshold described above can each be adjusted or varied eitherautomatically or based on user input. The filter parameters can bevaried based on a type of welding process implemented by the weldingsystem 100 and/or a particular user of the welding system 100. Thefilter parameters can be adjusted based on different current ranges suchthat relatively higher operational currents are associated with a firstset of filter parameters and relatively lower operational currents areassociated with a second, different set of filter parameters. The filterparameters can also be adjusted based on the type of accessory equipment(e.g., consumables) used during a particular process—such as, forexample, a type of electrode or workpiece being welded.

The filter parameters can also be varied based on additional outputinformation including, for example, an output power and/or outputcurrent. Further, the filter parameters can be adjusted on a staticbasis or a dynamic basis. That is, the filter parameters can be set ormodified before and after a particular welding process (e.g., maintainedas fixed or set during the entirety of a welding process) or can beadjusted continuously on the fly during the welding process (i.e.,dynamically as conditions may change during a welding process).

The filter parameters can also be varied based on the type of materialbeing welded. For example, it may be desirable to break or extinguish anarc differently based on different types of material. For certain typesof materials, a lower or higher output may or may not be tolerable priorto ending an arc. If an output voltage in the ending stage of an arc istoo high, then for some materials the result can be a long and dancingarc, which can introduce problems with the quality and reliability ofthe weld. Accordingly, filter parameters can be based on the types ofmaterials to be welded. The type of material being welded can beprovided to the welding system 100 (e.g., through user input) or can beautomatically determined. In various embodiments, a machine visionsystem and/or other material detection system can be used by the weldingsystem 100 to determine a type of material to be welded such that thefilter parameters can be adjusted based on knowledge of the same.

FIG. 2 illustrates an exemplary monitoring/filtering process 200according to techniques described herein. The monitoring/filteringprocess 200 can be implemented by the welding system 100 depicted inFIG. 1 .

As shown in FIG. 2 , an output 202 of a welding system can be tracked ormonitored. The output 202 can be an arc voltage output of a weldingpower supply. The arc voltage 202 can be monitored continuously overtime as indicated in FIG. 2 .

Two monitoring/filter parameters are shown in FIG. 2 . The firstparameter 204 can be a threshold parameter value. The thresholdparameter 204 can be an arc voltage threshold level or value. As shownin FIG. 2 , the arc voltage 202 can vary substantially over time and canhave a value greater than or less than the arc voltage threshold value204.

A second parameter 206 can be a time threshold 206. The time threshold206 can be considered to be a temporal threshold or a filter time.Operation of a welding system in view of the techniques depicted in FIG.2 can be described as follows. When the arc voltage 202 exceeds thethreshold level 204, a timer can begin. The timer can track how long thearc voltage 202 exceeds the threshold level 204. When the amount of timethat the arc voltage 202 exceeds the threshold level 204 is greater thanthe filter time threshold 206, an arc stop or arc break can beinitiated. Specifically, an output current can be stopped or blocked,such that the output arc is broken or extinguished. This is shown by thedecay region 208 of the arc voltage 202. When the filter time threshold206 has been met, a power source of the welding system can be shut down.As a result, the arc voltage 202 can diminish sharply (as shown byregion 208). The output arc 202 can then be broken and/or extinguished.Subsequent to the decay region 208, the power source can be re-engagedso as to be ready to provide an output arc when instructed to do so. Theamount of time between shutting down the power source and re-engagingthe power source can be set to be approximately a few milliseconds withthe delay time being configurable and adjustable based on a variety offactors.

As described above, the output threshold 204 and temporal threshold 206can each be separately adjusted, configured, or modified statically ordynamically based on a number of factors including the welding processor even the particular user of a welding machine. By employing themonitoring/filtering mechanism described herein, unwanted arc breaks canoccur less frequently while desired arc breaks can still be provided ina quick and reliable manner. Further, by providing the ability to adjustthe output threshold 204 and the temporal threshold 206, a weldingsystem can provide these benefits over a wide range of processes, users,current ranges, and operational conditions.

Overall, the techniques described herein provide for cutting orextinguishing an output arc when desired by a welder. The output arc canbe extinguished as desired based on the welder's movement of theelectrode relative to the workpiece. The techniques described herein cancontinuously monitor the output of a welding system and can determinewhen to cut the output arc based on a number of parameters such as, forexample, an output current, output voltage, and/or output power. Theparameters can be viewed as filtering the observed output of the weldingsystem to determine when to break an output arc (or alternatively whento maintain an arc) as the electrode is moved relative to the workpiece.The comparison of the adjustable parameters to the observed weldingsystem output or use of the parameters in view of the welding systemoutput can be implemented in a number of ways including, for example,through a filter or filter function. Filters such as a low pass filterof a first degree, a low pass filter of a higher degree, and/or a sum ofdifferent low pass filters can be used. Further, an input to the filterscan itself be a mathematical function with any of the above-mentionedparameters used as variables.

The present disclosure is not to be limited in scope by the specificembodiments described herein. Indeed, other various embodiments of andmodifications to the present disclosure, in addition to those describedherein, will be apparent to those of ordinary skill in the art from theforegoing description and accompanying drawings. Thus, such otherembodiments and modifications are intended to fall within the scope ofthe present disclosure. Furthermore, although the present disclosure hasbeen described herein in the context of a particular implementation in aparticular environment for a particular purpose, those of ordinary skillin the art will recognize that its usefulness is not limited thereto andthat the present disclosure may be beneficially implemented in anynumber of environments for any number of purposes. Thus, the claims setforth below should be construed in view of the full breadth and spiritof the present disclosure as described herein.

What is claimed is:
 1. A method, comprising: monitoring an output arcvoltage between a workpiece and a welding electrode of a welding systemduring a welding operation; determining that the welding electrode hasbeen retracted from the workpiece by detecting that the output arcvoltage has exceeded a voltage threshold level, indicating an increasedarc length between the welding electrode and the workpiece; triggering atimer when the output arc voltage exceeds the voltage threshold level;and determining that the output arc between the workpiece and thewelding electrode is to be extinguished and stopping an output weldcurrent of the welding system in response to the output arc voltagecontinuously remaining above the voltage threshold level until a valueof the timer exceeds a temporal threshold.
 2. The method of claim 1,further comprising: determining that the welding operation is to becontinued and maintaining the output arc with the output weld current inresponse to the output arc voltage falling below the voltage thresholdlevel before the value of the timer exceeds the temporal threshold. 3.The method of claim 1, wherein the voltage threshold level and thetemporal threshold are adjusted statically.
 4. The method of claim 1,wherein the voltage threshold level and the temporal threshold areadjusted dynamically.
 5. The method of claim 1, wherein the voltagethreshold level and the temporal threshold are adjusted based on acomposition of the workpiece.
 6. The method of claim 1, wherein thevoltage threshold level and the temporal threshold are adjusted based onan expected current range.
 7. The method of claim 1, wherein the voltagethreshold level and the temporal threshold are adjusted based on a kindof welding employed in the welding process.
 8. The method of claim 7,wherein the kind of welding is Manual Metal Arc (MMA) welding.
 9. Themethod of claim 1, wherein the voltage threshold level and the temporalthreshold are adjusted based on an electrode used during a weldingprocess.
 10. The method of claim 1, wherein stopping the output weldcurrent of the welding system comprises shutting down a power source.11. The method of claim 10, wherein the power source is turned back onafter a predetermined delay.
 12. A method comprising: monitoring anoutput arc voltage between a workpiece and a welding electrode of awelding system during a welding operation; in response to the output arcvoltage continuously exceeding a voltage threshold level for a period oftime that exceeds a temporal threshold, determining that the weldingelectrode has been retracted from the workpiece with an intent toextinguish the output arc between the workpiece and the weldingelectrode, and stopping an output weld current of the welding system;and in response to the output arc voltage failing to continuously exceedthe voltage threshold level for the temporal threshold, determining thatthe welding operation is to be continued and maintaining the output arcwith the output weld current.
 13. The method of claim 12, wherein thevoltage threshold level and the temporal threshold are adjustedstatically.
 14. The method of claim 12, wherein the voltage thresholdlevel and the temporal threshold are adjusted dynamically.
 15. Themethod of claim 12, wherein the voltage threshold level and the temporalthreshold are adjusted based on an expected current range.
 16. Themethod of claim 12, wherein the voltage threshold level and the temporalthreshold are adjusted based on a type of welding employed in thewelding process.
 17. A welding system, comprising: an output monitorcoupled to a welding electrode connected to the welding system, theoutput monitor being configured to: monitor an output arc voltagebetween a workpiece and the welding electrode of the welding systemduring a welding operation; and determine that the welding electrode hasbeen retracted from the workpiece by detecting that the output arcvoltage has exceeded a voltage threshold level, indicating an increasedarc length between the welding electrode and the workpiece; and acontrol module coupled to the output monitor and configured to:determine that the the output arc between the workpiece and the weldingelectrode is to be extinguished and stop the output weld current inresponse to the output arc voltage continuously exceeding the voltagethreshold level for a period of time that exceeds a temporal threshold.18. The welding system of claim 17, wherein the control module isfurther configured to: determine that the welding operation is to becontinued and maintain the output arc with the output weld current inresponse to the output arc voltage failing to continuously exceed thevoltage threshold level for a period of time that exceeds the temperalthreshold.
 19. The welding system of claim 17, wherein the voltagethreshold level and the temporal threshold are adjusted based on anexpected current range.
 20. The welding system of claim 17, wherein thevoltage threshold level and the temporal threshold are adjusted based ona kind of welding employed in the welding process.